Cleansing the skin is very important for facecare, and it should be as effective as possible since fatty residues such as excess sebum, residues of cosmetic products used daily and makeup products, in particular waterproof products, accumulate in the folds of the skin and can block the pores of the skin and lead to the appearance of spots.
The foaming cleansing products currently marketed are in the form of foaming bars, gels or creams, and they may or may not contain soaps. Some consumers complain that foaming products containing soaps cause tautness due to them being too detergent. It is therefore often preferable to prepare foaming products without soaps so as to have better tolerance. The cleansing products not containing soaps which are currently on the market generally have a low viscosity and, as a result, are not always practical to use because they have a tendency to run.
In order to thicken soap-free foaming products it is known practice to add, to the latter, thickeners such as oxyethylenated compounds, polymers, for instance cellulose gums or derivatives thereof, guar gums or derivatives thereof, acrylic polymers, including those possibly containing a hydrophobic portion and therefore having an amphiphilic character. Thus, document EP-A-1,172,095 describes a foaming composition containing silica and an oxyethylenated compound such as, for example, PEG-120 methyl glucose dioleate.
However, when the percentage of these thickening compounds is increased so as to have a thicker composition, this brings about drawbacks. Thus, when the percentage of oxyethylenated compounds is increased, the spreading over the skin occurs in packets and is not homogeneous. When the percentage of acrylic polymer is increased, the products obtained can be viscous, but result in a mediocre beginning of lathering. Moreover, the addition of too high percentage of gum causes the start of lathering to be impaired and affects the qualities of the foam.
It is therefore difficult to thicken foaming media while at the same time conserving the required properties, i.e. good mixing with water and a rapid conversion to foam, and homogeneous spreading when applied to the skin.